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   Home » Melquiades Amplifier » DHT driver & input (26 posts, 2 pages)
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  »  New  Lamm Industries: a special interview with a special com..  I do not think so but I migh be wrong....  Audio News Forum     94  1075622  09-18-2005
  »  New  About destiny of “High-End Sound”...  Got today via email....  Playback Listening  Forum     6  52231  01-19-2007
  »  New  A contemporary AD1 Triode by Emission Labs..  Yamamoto, AD1 and no talk about time-alignment....  Audio Discussions  Forum     6  77593  10-12-2007
  »  New  My (Amplification + Acoustic System): what is next?..  Macondo and Melquiades in the NEW room....  Audio Discussions  Forum     41  239668  01-10-2008
  »  New  Single-stage Melquiades vs. DHT amps..  A hallucination?...  Melquiades Amplifier  Forum     397  2925428  11-22-2008
  »  New  About the life-expectancy of the new production tubes...  Stressing the damn contemporary tubes....  Audio Discussions  Forum     9  72298  12-29-2008
  »  New  The period DHT tubes and Swastika..  Maybe there is another solution...  Melquiades Amplifier  Forum     1  20581  04-30-2009
  »  New  The DHOFT topology? Do not try it home...  A medley of slow-cooked triodes....  Melquiades Amplifier  Forum     3  36190  05-04-2009
  »  New  Why the tubes shall be the same?..  Not optional anymore?...  Melquiades Amplifier  Forum     7  46633  05-11-2009
  »  New  A full-range quality-triode? Does Size mater?..  A full-range quality-triode? Does Size mater?...  Melquiades Amplifier  Forum     0  12732  12-02-2009
01-31-2009 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,722
Joined on 05-27-2004

Post #: 21
Post ID: 9592
Reply to: 9573
ThE 10S TUBES
fiogf49gjkf0d
 gordan wrote:
plus they IMHO sound better - less prejudiced towards a romantic SET sound we all know (and some try to avoid).
Yes, Gordan, it is exactly what I heard about the 10s from the sources that I found rational. The huge plate impedance and a need of very high ration transformer is something that might stop some people who would like to drive 10 full-range but for DSET application it might be a very good tube. BTW, there were a huge variety of the 10 rubes made. Even the 10Y – there were too many of them that were too different. I am still contemplating to get 40K-50K transformer and to try the 10s before I decide where to go with my amps for MF channel. No on sadly makes off the shelf 40K transformer with limited inductance for DSET applications…

The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
01-31-2009 Post does not mapped to Knowledge Tree
guy sergeant
United Kingdom
Posts 260
Joined on 08-03-2004

Post #: 22
Post ID: 9595
Reply to: 9592
DHT driving the 801 or 10Y
fiogf49gjkf0d
Driving an 801 or 10Y with another DHT would be tricky. The driver stage would need a Zout of <400 ohms. A 2A3 might do it via a step down interstage although making a good interstage that'll handle 60mA will be difficult. A 45 at near maximum ratings via a 2:1 step down might also just do it (but not with much to spare)  The smaller DHT's just wouldn't swing enough volts once the necessary step down was applied.  Shishido used the 6EM7 and a step down but that isn't a DHT.

01-31-2009 Post does not mapped to Knowledge Tree
floobydust


currently roaming the US
Posts 62
Joined on 01-19-2009

Post #: 23
Post ID: 9596
Reply to: 9592
How high is too high?
fiogf49gjkf0d
 Romy the Cat wrote:
 gordan wrote:
plus they IMHO sound better - less prejudiced towards a romantic SET sound we all know (and some try to avoid).
Yes, Gordan, it is exactly what I heard about the 10s from the sources that I found rational. The huge plate impedance and a need of very high ration transformer is something that might stop some people who would like to drive 10 full-range but for DSET application it might be a very good tube. BTW, there were a huge variety of the 10 rubes made. Even the 10Y – there were too many of them that were too different. I am still contemplating to get 40K-50K transformer and to try the 10s before I decide where to go with my amps for MF channel. No on sadly makes off the shelf 40K transformer with limited inductance for DSET applications…

The Cat


 Trying to build an OPT with a very high impedance becomes difficult at best. The capacitance builds up from the additional layers and you get a bad HF roll-off and slew rate limiting. While I was reading your post, one odd thought came to mind. Perhaps get a pair of 10K - 15K OPTs with 16 ohm secondaries. Wire the primaries in series and the secondaries in parallel. Just a thought...

 Regarding the 10S... the 1602 is a near identical replacement.

 Regards, KM



... just because you're paranoid, it doesn't mean they're not after you ...
01-31-2009 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,722
Joined on 05-27-2004

Post #: 24
Post ID: 9597
Reply to: 9596
….and it might not be always a good thing
fiogf49gjkf0d
Actually my leading though how to put one ass on all impedance chars is to have 5K primary with 12-16 coils of secondary. The 4K would be fine load for 2A3 type of pates. It would not be difficult to remap the secondaryes to get 7K-8K that would be OK most likely demanding for YO186. And then if I would like to jump to 10s with their very high plate impedance and the need of 30-50K load then I might use some OPT’s secondary as primary and had a huge transforming ratio. The only thing that holds me is that I do not need this transformer for a long run. To drive MiniMe’s HF section I need a cheap and easy available tube, obviously it will not be 10 or YO186. For the DSET use in Melquiades I would not need too much turns to built up inductance and I do not need bass in there. For Melquiades channel it shell be just enough turns in primary to get the coupling. I might even consider to make as it was done in my FH channel – just one turn of primary foul and to cover it with a layer of secondary. Yes, there are many ambiguous ways to do the things and I have no desire to actually try them – this is my problem. I also pressmen that a performance of a tube and OPT in a full-range application and in HF DSET application might be different as the sigals doe not have LF modulation in second case… and it might not be always a good thing. Go figure…

The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
11-30-2010 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,722
Joined on 05-27-2004

Post #: 25
Post ID: 15029
Reply to: 3619
What makes eye on the tube getter?
fiogf49gjkf0d
One of my YO186 have developed a dark eye on it’s getter. Even the tube still measures fine and sound fine but I wonder what make some of those tubes to get dart spat of the getter gloss. I have seen it before and do not have any association between the presence of the dark eyes and the tube quality, still I would like to know where this anomaly come from and if is it a sign of anything.

TubeCancer.JPG

Rgs, Romy the Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
11-30-2010 Post does not mapped to Knowledge Tree
AOK_Farmer


Marlboro NY USA
Posts 64
Joined on 07-08-2004

Post #: 26
Post ID: 15030
Reply to: 15029
Effects of radiation
fiogf49gjkf0d
Romy
It looks like the getter material has been vaporized off the center of the eye area by electron impact and redeposited nearby just outside the eye in a thickening are thats is very reflective because of it's thickness. Like a moon crater.
Steve
Page 2 of 2 (26 items) Select Pages:  « 1 2
   Target    Threads for related reading   Most recent post in related threads   Forum  Replies   Views   Started 
  »  New  Lamm Industries: a special interview with a special com..  I do not think so but I migh be wrong....  Audio News Forum     94  1075622  09-18-2005
  »  New  About destiny of “High-End Sound”...  Got today via email....  Playback Listening  Forum     6  52231  01-19-2007
  »  New  A contemporary AD1 Triode by Emission Labs..  Yamamoto, AD1 and no talk about time-alignment....  Audio Discussions  Forum     6  77593  10-12-2007
  »  New  My (Amplification + Acoustic System): what is next?..  Macondo and Melquiades in the NEW room....  Audio Discussions  Forum     41  239668  01-10-2008
  »  New  Single-stage Melquiades vs. DHT amps..  A hallucination?...  Melquiades Amplifier  Forum     397  2925428  11-22-2008
  »  New  About the life-expectancy of the new production tubes...  Stressing the damn contemporary tubes....  Audio Discussions  Forum     9  72298  12-29-2008
  »  New  The period DHT tubes and Swastika..  Maybe there is another solution...  Melquiades Amplifier  Forum     1  20581  04-30-2009
  »  New  The DHOFT topology? Do not try it home...  A medley of slow-cooked triodes....  Melquiades Amplifier  Forum     3  36190  05-04-2009
  »  New  Why the tubes shall be the same?..  Not optional anymore?...  Melquiades Amplifier  Forum     7  46633  05-11-2009
  »  New  A full-range quality-triode? Does Size mater?..  A full-range quality-triode? Does Size mater?...  Melquiades Amplifier  Forum     0  12732  12-02-2009
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